The invention relates to a monitoring device and, particularly, to a monitoring device for detecting physiological events and for generating an audio and/or visual indication of the occurrence of the physiological event.
A tocodynamometer (xe2x80x9ctocoxe2x80x9d) or a uterine pressure catheter are commonly used to collect uterine activity or contraction data during a birthing event. In the case of a toco, the transducer is attached to a belt that is strapped to the mother""s abdomen. During a uterine contraction, the transducer is pressed between the abdomen and the belt and a contraction is registered. In the case of the intrauterine pressure catheter, an intrauterine pressure sensor is inserted by catheter through the birth canal and into the uterus. The sensor registers the change in uterine pressure that occurs during a contraction.
A signal from the toco or IUP transducer is referred to as a uterine activity signal, which may contain information indicative of uterine contractions. The uterine activity signal is sampled by the fetal monitor and plotted or trended over time on a strip chart. Uterine contractions appear as humps in the waveform shown on the strip chart. Alternatively, the maternal/fetal monitor can visually display a portion of the uterine activity waveform on a monitor screen as well as displaying an instantaneous pressure.
Another sensor that may be used during a birthing event is a fetal pulse oxygen saturation (xe2x80x9cFSpO2xe2x80x9d) sensor. The FSpO2 sensor utilizes an infrared sensor to measure an amount of oxygen within a patient""s blood. During a birthing event, the FSpO2 sensor is inserted by catheter through the birth canal into the uterus and measures the amount of oxygen within a fetus"" blood while the fetus is in the mother""s uterus.
The invention provides a means for informing a clinician of when a uterine contraction is beginning or ending. This information is important when inserting or repositioning the FSpO2 sensor. Inserting or repositioning the FSpO2 sensor while a uterine contraction is occurring may result in loss of data and added patient discomfort. The invention is an improvement over prior art monitors because the clinician does not need to be looking at the monitor display or at the strip chart to determine if a contraction is occurring. An audio indicator on the user interface of the monitor would alert the clinician as to the onset of a uterine contraction.
Another problem that arises with prior art maternal/fetal monitors is that the trending of the strip chart is a retrospective interpretation of the birthing event. Due to the low trending rate of the strip chart, it may be unclear whether a uterine contraction is occurring without a physical examination. Moreover, the clinician must visually inspect the strip chart for a period of time and compare the currently sampled data with previous baseline data to determine if a contraction is occurring. Thus, the clinician may not be certain that a uterine contraction is beginning.
For example, if the mother is under epidural or some other anesthesia, she may not be aware that a contraction is occurring. In addition, if the clinician is not continuously inspecting the strip chart pressure display, or the material abdomen, then the clinician may also not be aware that a contraction is occurring. This may result in the clinician informing the patient to contract uterine and vaginal muscles (i.e., xe2x80x9cpushxe2x80x9d) at an improper time. By providing an indicator, the clinician can be more informed as to when a contraction is occurring and, therefore, can inform the laboring mother to xe2x80x9cpushxe2x80x9d at the proper time during the contraction.
Accordingly, the invention provides a medical device, including an input terminal for connection to a patient to acquire a uterine activity signal having at least one uterine contraction, an analysis module including a processor and software for operating the processor to determine an occurrence of an event relating to the uterine contraction and to generate a signal upon the occurrence of the event, and an indicator that receives the signal and provides to a user an indication of the event in response to the signal. The indicator may be a visual indicator or an audible indicator.
In a first embodiment, the software further operates the processor to determine a second event relating to the uterine contraction, and to generate a second signal upon the occurrence of the second event. In addition, the indicator receives the second signal and provides to a user an indication of the second event in response to the signal.
In a second embodiment, the software further operates the processor to determine a second event relating to the uterine contraction, and to terminate generation of the signal upon the occurrence of the second event.
In a third embodiment, the software operates the processor to determine when a maximum amplitude of the uterine contraction occurs, and to generate a second signal upon occurrence of the maximum amplitude. In addition, the indicator receives the second signal and provides to a user an indication of the maximum amplitude in response to the second signal. Furthermore, for the third embodiment, the software operates the processor to determine a second event relating to the uterine contraction, and to generate a third signal upon the occurrence of the second event. The indicator receives the third signal and provides to a user indication of the second event.
The invention further provides a medical device for acquiring and analyzing a physiological signal having at least one physiological event. The medical device includes an input terminal for connection to a patient to acquire the physiological signal, means for a determining the beginning of the physiological event and for generating a signal indicating the beginning of the physiological event, and an indicator that receives the signal and provides to a user an indication of the beginning of the physiological event in response to the signal.
The invention further provides a method of analyzing a physiological signal based on at least one physiological event. The method comprises the acts of obtaining the physiological signal, determining the onset of the physiological event, and generating a signal in response to the onset of the physiological event.
The invention further provides a method of notifying a clinician to instruct a patient to perform an action during a birthing event. The method includes the acts of providing a medical device including a uterine activity sensor, an analysis module and an indicator; attaching the uterine activity sensor to the patient; acquiring a uterine activity signal from the patient with the uterine activity sensor, the uterine activity signal having at least one uterine contraction; determining an occurrence of an event relating to the uterine contraction with the analysis module; generating an indicator signal with the analysis module upon the occurrence of the event; providing the indicator signal to the indicator; and instructing the patient to perform an action in response to the signal being provided to the indicator.
Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims, and drawings.